This invention relates to a storefront formed from a support framework of upright mullions and horizontal supports which support glass panels; and more particularly to the shape of the mullions and horizontal supports, to the support clips used for the dual purposes of mounting the horizontal supports to the mullions and of supporting the glass panels, and to the attachment clips which extend from the support framework between the glass panels for connecting cover plates to the support framework to cover the edge portions of the glass panels.
The typical prior art storefront construction which holds a plurality of glass panels in a support framework usually comprises a plurality of upright mullions and horizontal supports which form the support framework, with the mullions connected securely at their tops and bottoms to headers and plates and the horizontal supports connected at their ends to the mullions, with the horizontal supports mounted on brackets that are fastened to the mullions. The glass panels are mounted against the exterior surface of the framework and cover plates are mounted over the adjacent edges of the glass panels. The cover plates are connected by fasteners to the framework between the glass panels.
It is desirable to have the horizontal supports securely mounted to the mullions of a storefront so as to firmly support the glass panels along their horizontal edges as well as their vertical edges, so that when abrupt air pressures are applied to the glass panels by wind, etc., the glass panels will not crack or otherwise become damaged, and so that the assembly will not leak water. Also, it is desirable to minimize the transfer of heat from one side of the storefront to the other side so as to minimize the energy utilized in maintaining the interior of the space in the desired temperature range.
The prior art storefront structures usually include metal mullions and metal horizontal supports, and brackets are screwed to the mullions so that the horizontal supports are mounted at their ends to the brackets. This arrangement sometimes results in the horizontal supports being loosely connected to the mullions so that the horizontal supports tend to become twisted or displaced during the assembly of the storefront and only the mullions provide a secure support for the glass panels. Moreover, the use of brackets to fasten the horizontal supports to the mullions usually requires screws or other fasteners that are exposed externally of the framework. The screws are subject to rust and deterioration, and it is desirable to counter-sink the screws in the material and to use flathead screws so as to avoid forming that is not appealing from a visual standpoint.
After the glass panels have been applied to the support framework, the cover plates are placed over the edges of the glass panels by fasteners that extend from the cover plates between the glass panels to the support framework. The fasteners tend to transfer heat between the support framework which usually is located inside the building and the cover plates which usually are located outside the building.